This invention relates to latching mechanisms and relates more specifically to a latching mechanism having a rotary latch that is manually movable between latched and unlatched positions.
One such latching mechanism is shown in U.S. Pat. No. 3,596,954, wherein a latch is rotatably mounted by means of a stud or axle in an elongated housing constituting the base of a handle for a sliding door, and is formed with a latching hook on one end and an operating handle on the other. When the handle is rocked in one direction, the latch hook is extended through a slot in the front wall of the housing for latching engagement with a keeper on the door frame. The latch is held in this position by a spring, until the handle is rocked in the opposite direction, disengaging the latch hook from the keeper and retracting it into the housing.
For increased security against forced entry, the unit in the aforesaid patent also has a holddown finger, or anti-liftout key, extending through a second slot in the front wall of the housing for insertion in a corresponding slot in the keeper. When so inserted, the holddown finger prevents lifting of the door which otherwise might allow the latch hook to be pressed out of the latched position.
It sometimes is possible, however, to force such a latch open by inserting a tool between the door and the door frame and pressing the latch hook back against the spring action. The primary objective of the present invention is to incorporate in a latching mechanism of the foregoing general character a relatively simple and inexpensive locking device that substantially increases the security achieved with such a latch.